ClickHouse/dbms/include/DB/DataStreams/TabSeparatedRowInputStream.h

#pragma once

#include <DB/Core/Block.h>
#include <DB/DataStreams/IRowInputStream.h>


namespace DB
{

class ReadBuffer;


/** Поток для ввода данных в формате tsv.
  */
class TabSeparatedRowInputStream : public IRowInputStream
{
public:
	/** with_names - в первой строке заголовок с именами столбцов
	  * with_types - на следующей строке заголовок с именами типов
	  */
	TabSeparatedRowInputStream(ReadBuffer & istr_, const Block & sample_, bool with_names_ = false, bool with_types_ = false);

	bool read(Block & block) override;
	void readPrefix() override;
	bool allowSyncAfterError() const override { return true; };
	void syncAfterError() override;

	std::string getDiagnosticInfo() override;

private:
	ReadBuffer & istr;
	const Block sample;
	bool with_names;
	bool with_types;
	DataTypes data_types;

	/// Для удобной диагностики в случае ошибки.

	size_t row_num = 0;

	/// Сколько байт было считано, не считая тех, что ещё в буфере.
	size_t bytes_read_at_start_of_buffer_on_current_row = 0;
	size_t bytes_read_at_start_of_buffer_on_prev_row = 0;

	char * pos_of_current_row = nullptr;
	char * pos_of_prev_row = nullptr;

	void updateDiagnosticInfo()
	{
		++row_num;

		bytes_read_at_start_of_buffer_on_prev_row = bytes_read_at_start_of_buffer_on_current_row;
		bytes_read_at_start_of_buffer_on_current_row = istr.count() - istr.offset();

		pos_of_prev_row = pos_of_current_row;
		pos_of_current_row = istr.position();
	}

	bool parseRowAndPrintDiagnosticInfo(Block & block,
		WriteBuffer & out, size_t max_length_of_column_name, size_t max_length_of_data_type_name);
};

}